(a) The conventional strain in a member subjected to a tensile stress of 14,815 psi is 0.350. Calculate the true stress and the true strain. Assuming constant volume.

(b) The original diameter of a tension specimen is 0.505 inches (figure 115.4). At a certain load, the diameter is found to be 0.388 inches. Calculate the true and conventional strain at this point. Assuming constant volume.

The strings:
S7P3A31 (Force - Pull).

The math:
Pj Problem of Interest is of type force (pull).

Formulas of interest:
Conventional (also called nominal, or engineering) stress, σ = Load/AoWhere Ao is original cross-section area of member
Conventional(also called nominal, or engineering) strain, ε = δ/loWhere l0 is original length of member
True stress, σ' = Load/A'
Where A' is actual area of the cross-section corresponding to the given load.
True (also called natural) strain, ε' = loge(Ao/A') = loge(1 + ε)